Heretofore speed bumps have been installed on roads particularly in congested areas where it is desired that the vehicles travel at a relatively slow speed. These speed bumps are often installed in large parking lots, school zone, apartment building complexes, etc.
One problem with such speed bumps is that they are normally constructed of asphalt and project above the road surface approximately six to eight inches. In order to pass over these speed bumps without imparting substantial jar to the vehicle, the speed of the vehicle must be reduced to approximately five miles an hour in some instances. Even when the speed of the vehicle has been reduced, a substantial jar is often imparted to the vehicle and in some cases the speed bump strikes the frame of the vehicle.
In order to overcome these undesirable disadvantages attempts have been made to produce retractible safety speed bumps such as disclosed in U.S. Pat. No. 4,012,157. Such a speed bump is provided to be nested into a recess when not in use. Another removable speed bump is disclosed in U.S. Pat. No. 1,688,409. In this particular device the speed bump is pivoted out of the path of the vehicles when not in use.